Response of drought index to land use types in the Loess Plateau of Shaanxi, China

Drought is influenced by numerous factors, and traditional studies have only considered meteorological factors, but human activities are also an important influencing factor. From 1980 to 2010, the reform and opening up and the project of returning farmland to forest have largely changed the land use type of Loess Plateau in Shaanxi. In order to study the influence of land use types on drought in the study area, 8 stations with different land use types were selected based on remote sensing data and meteorological data. Based on univariate linear regression, the response of the drought index SPI to land use types was analyzed sequentially in each of the five time stages. The results showed that from 1980 to 2000, forest had the greatest drought intensity, followed by arable land and town and country. However, the response of arable land to the drought index was the greatest, followed by town and country. Forest had the weakest response to the drought index. From 2000 to 2010, the greatest degree of drought was observed in forest, followed by town and country and arable land. And forest has the strongest response to the drought index, followed by town and country, and finally, arable land. The area of forest, grass and town and country keeps increasing. The area of arable land is decreasing year by year. Land use types are constantly undergoing complex transformations. The drought index responds strongly to the change of both arable land to grass and arable land to town and country, while it responds weakly to the mutual transformation of both grass and town and country. In the areas where meteorological conditions are difficult to change, the local drought is considered to be improved by changing the substrate type.